Pre-measured amounts of detergent compositions which are compressed into water-soluble tablet form are well known and have received substantial commercial acceptance. They generally comprise a cleaning agent such as a synthetic detergent or soap and a detergency builder which is generally sodium tripolyphosphate (STP), along with suds builders, soil suspending agents and other ingredients commonly added to washing compositions. They are easy to use, avoid the problem of spillage during use, and prevent the use by the consumer of too much or too little detergent. However, manufactures of dishwashers (especially in the US) produce a wide variety dispenser cups. They vary in shape and size. We have found that certain oval shapes are preferred because they are more likely to be released from the cup into the wash water. Therefore the entire pre-measured amounts of detergent compositions will be dissolved quickly at the beginning of the main wash cycle leading to better cleaning performance. Some tablet compositions may eventually dissolve out of the cup due to the action of hot water in the machine. However, other compositions may cake in the cup and not dissolve completely. It is widely recognized that it is most desirable to have the tablet enter the main wash as soon as possible. This will allow the cleaning agents maximum time to clean dishes and silverware.
U.S. Pat. No. 3,557,003 teaches a detergent tablet containing a builder salt, an inorganic salt, surfactant and an alkali metal soap.
U.S. Pat. No. 3,423,322 teaches a tablet containing sodium tripolyphosphate, surfactant and potassium phosphate.
U.S. Pat. No. 5,133,892 teaches a multi layer tablet which allows the incorporation of both bleach and enzyme.
The present invention teaches a powdered dishwashing composition in the form of an elliptically shaped tablet which is easily dispensed from the cup of the automatic dishwasher and is readily soluble in the wash solution of an automatic dishwashing machine.